Biomedical subjects

H C Liu

Publications and source records attributed to H C Liu.

At least 91 records · Page 5Linked to original sources

PubMed1999

In-vitro and in-vivo evaluation of the drug-drug interaction between fluvoxamine and clozapine.

The drug-drug interaction between fluvoxamine (FLV) and clozapine (CLZ) was evaluated by in-vitro and in-vivo methods. In-vitro studies were conducted using human hepatic microsomal preparations with standard chemical inhibitors of the cytochrome P450 (CYP 450) isozyme system. Furafyline, FLV, troleandomycin (TAO) and erythromycin were used as the chemical inhibitors. For the in-vivo study, nine male schizophrenic patients were administered a single dose of CLZ 50 mg on two separate occasions with a 2-week FLV treatment of 50 mg twice a day in between each CLZ dose. Blood samples were obtained over 48 h following CLZ administration. CLZ and its two principle metabolites, clozapine N-oxide (CNO) and desmethylclozapine (DCLZ), were measured by high performance liquid chromatography with ultraviolet detection for both in-vitro and in-vivo studies. The in-vitro formation of DCLZ was inhibited by furafyline and FLV by 42.0% and 48.5% (P<0.01), respectively. TAO and erythromycin had only modest inhibition effects on DCLZ formation of 18.3% and 21.0% (P = NS), respectively. CNO in-vitro formation was significantly reduced by TAO and erythromycin by 44.5% and 45.0% (P<0.01), respectively. Furafyline and FLV had only modest effects of 19.2% and 8.5% (P = NS), respectively. In schizophrenic patients, FLV resulted in a pronounced increased in CLZ plasma concentrations with the total mean CLZ AUC increased by a factor of 2.58 from 780.8 ng/ml per hour to 2218.0 ng/ml per hour (P<0.001). All patients were sedated during combined FLV and CLZ use. During FLV treatment, CNO and DCLZ AUC both decreased by 18.8% (P = 0.07) and 9.0% (P = NS), respectively. These results indicate that in-vitro evaluations may not always accurately reflect changes in drug-drug interaction observed in-vivo. Careful patient monitoring is recommended during FLV/CLZ co-administration.

Adult↗

PubMed1999

Human endometrial stromal cells improve embryo quality by enhancing the expression of insulin-like growth factors and their receptors in cocultured human preimplantation embryos.

OBJECTIVE: To demonstrate the mechanism by which human endometrial stromal cells improve embryo quality in coculture. DESIGN: Randomized study. SETTING: Academic research center. PATIENT(S): Patients undergoing IVF-ET. INTERVENTION(S): Donated human embryos were cultured randomly either alone (group A) or with human endometrial stromal cells (group B), and the embryonic expression of insulin-like growth factors (IGFs) and their receptors was detected by reverse transcriptase polymerase chain reaction after culture. MAIN OUTCOME MEASURE(S): The embryo frequency distribution of groups A and B before and after culture and the embryonic transcripts of the IGF family genes of the two study groups after culture were compared. RESULT(S): The embryo frequency distribution of the day 3 embryonic stages in groups A and B was not different. However, after culture, a statistically significant difference in blastocyst formation was observed between groups A and B. A significant increase in the expression of IGF-1, IGF-2, the IGF-1 receptor, and the insulin-receptor also was noted. Among the embryos that reached the blastocyst stage, the expression of IGF-1 and the IGF-1 receptor also was significantly different in the two study groups. CONCLUSION(S): Human endometrial stromal cells enhanced the expression of IGFs and their receptors in cocultured human embryos, which may be essential for improving embryo quality.

Blastocyst↗

PubMed1999

The embryo toxicity of hydrosalpinx fluid is only apparent at high concentrations: an in vitro model that stimulates in vivo events.

OBJECTIVE: To simulate the in vivo model in studying the effect of hydrosalpinx fluid on embryonic development. DESIGN: Controlled prospective study. SETTING: Academic research center. PATIENT(S): Five hundred eighty-seven two-cell murine embryos. INTERVENTION(S): Embryos were grown under two sets of conditions. Half were cultured using 10% fetal calf serum in RPM1 medium in varying concentrations of hydrosalpinx fluid (0, 1%, 10%, 50%, 75%, and 100%). To more closely mimic the in vivo environment, the other half were grown in an endometrial coculture system with the same media and hydrosalpinx fluid concentrations. MAIN OUTCOME MEASURE(S): Embryonic development. RESULT(S): For each stage of embryogenesis, diminished development was noted with increasing concentrations of hydrosalpinx fluid. In the group of embryos grown without endometrial coculture, only at a minimum concentration of 50% hydrosalpinx fluid was diminished development noted for the blastocyst, hatching, and outgrowth stages. When an endometrial coculture system was used, development was not inhibited until exposure to a minimum of 75% hydrosalpinx fluid. Embryogenesis was enhanced when an endometrial coculture system was used for each concentration of hydrosalpinx fluid. CONCLUSION(S): When a model is used that more accurately mimics the in vivo conditions of IVF-ET in a patient with hydrosalpinges, it appears that high concentrations of hydrosalpinx fluid are required to signiticantly impede embryogenesis. The endometrium appears to help detoxify hydrosalpinx fluid.

Animals↗

PubMed1999

Recycling of a single human blastomere fixed on a microscopic slide for sexing and diagnosis of specific mutations by various types of polymerase chain reaction.

OBJECTIVE: To investigate the suitability of recycling single blastomeres to assess multiple genetic variables for preimplantation genetic diagnosis. DESIGN: Prospective randomized study. SETTING: An academic medical center. PATIENT(S): Patients undergoing IVF-ET. INTERVENTION(S): Blastomeres were disaggregated from donated embryos obtained from patients. MAIN OUTCOME MEASURE(S): Polymerase chain reaction (PCR) amplification products. RESULT(S): Fifty-eight blastomeres individually fixed on slides were separated into four groups. Sequential PCRs (group I, n = 30), primed in situ labeling (PRINS) before five sequential PCRs (group II, n = 10), staining with hematoxylin before performing five sequential PCRs (group III, n = 11) and preamplification of whole DNAs by degenerate oligonucleotide primer (DOP) before performing PCR were executed. The amplification efficiencies of five sequential PCRs were 100%, 100%, 96.6%, 83.3%, 56.7% for group I; 100% 100%, 100%, 80%, 40% for group II; 54.5%, 36.4%, 18.2%, 9.1% for group III; and 100%, 100%, 100%, 100%, 100% for group IV. CONCLUSION(S): Blastomeres fixed for PRINS can be recycled for PCR to obtain more genetic information. Hematoxylin staining appears to increase the incidence of failed amplification. Preamplification of whole genomic DNAs by DOP-PCR appears to facilitate diagnosis with high efficiency.

Blastomeres↗

PubMed1999

Protein kinase C isoforms during the development of deciduomata in pregnant rats.

In this study, we determined the expression of protein kinase C (PKC) isoforms during pregnancy. At pregnant duration, PKC alpha was down-modulated in the deciduomata but not in the myometrium. Down-modulation was compatible with the increase in cell mitosis, which reached a maximum at 8-9 days. On the other hand, PKC zeta was not down-modulated. It was increased both in the cytosolic and particulate fractions of the deciduomata, and paralleled the frequency of decidual cell mitosis. The other PKC isoform of delta was also increased, but it was associated with the cell regression. Therefore, these findings confirmed that the variable expression of PKC isoforms in decidualizing tissue may be involved in the modulation of decidual cell growth.

Animals↗

PubMed1999

The combined occluding effect of sodium fluoride varnish and Nd:YAG laser irradiation on human dentinal tubules.

Various methods and materials used in the treatment of dentin hypersensitivity are thought to achieve a therapeutic benefit by tubule occlusion. The aim of the present study was to evaluate the combined occluding effect of sodium fluoride varnish and Nd:YAG laser irradiation on human dentinal tubules. Thirty-six dentin specimens with exposed dentinal tubule orifices were used in this study. The samples were randomly divided into four groups. Groups A, B, and C were varnished by sodium fluoride, whereas group D served as a control. Then, group C was lased by 30 mJ of Nd:YAG laser, 10 pulses/s for 2 min by light painting. Three hours later, groups B and C were brushed by an electrical toothbrush for 30 min. Under SEM observation, the control group showed numerous exposed dentinal tubule orifices, and the sodium fluoride varnished specimens showed closure of exposed dentinal tubule orifices. After electrical toothbrushing, most of the sodium fluoride varnish was brushed away, except in the specimens that were irradiated by Nd:YAG laser. Over 90% of the dentinal tubule orifices were occluded by sodium fluoride varnish combined with Nd:YAG laser irradiation.

Combined Modality Therapy↗

PubMed1999

Revised memory and behavior problems checklist in Taiwanese patients with Alzheimer's disease.

The Revised Memory and Behavior Problems Checklist (RMBPC) is a 24-item caregiver report that measures observable behavioral and memory problems in dementia patients and their caregivers' reaction to these problems. The purpose of the present study was to evaluate the applicability of the RMBPC for use in Taiwanese patients with Alzheimer's disease (AD). The subjects included 76 AD patients (39 men and 37 women, mean age 72.3) and their caregivers (34 men and 42 women, mean age 53.5) who participated in a comprehensive assessment at the Veterans General Hospital-Taipei. The Chinese version of the Cognitive Abilities Screening Instrument was administered to the patients. Their caregivers rated the RMBPC and the short version of the Geriatric Depression Score (GDS). To assess the test-retest reliability, 30 caregivers rated a second RMBPC 3 days after the first evaluation. The mean score for the frequency rating on the RMBPC was 32.63 (SD = 12.44, range = 5-61) and the mean reaction score was 10.96 (SD = 11.53). The reaction score was significantly correlated with the GDS score (r = .363, p = .001). The Cronbach's alpha coefficients for frequency and reaction scores were .816 and .895 respectively. The test-retest reliabilities of total frequency and reaction scores were significantly correlated; overall correlations were .89 for frequency (p < .001) and .74 for reaction (p < .001). These findings suggest that the RMBPC be recommended as a reliable tool to assess behavioral and memory disturbance in Taiwanese AD patients.

Aged↗

PubMed1999

The effect of hydrosalpinges on IVF-ET outcome.

PURPOSE: Our purpose was to determine if the presence of a hydrosalpinx effects the outcome of in vitro fertilization (IVF)-embryo transfer. METHODS: We performed a retrospective analysis of IVF cycle stimulation sheets. RESULTS: A total of 1000 patients with tubal factor infertility was analyzed. There were 60 hydrosalpinx patients who underwent 116 initiated cycles with 106 embryo transfers, compared to 940 control patients undergoing 1428 initiated cycles with 1150 embryo transfers. Both groups had a similar response to ovarian stimulation, number of oocytes retrieved, and number of embryos transferred. The hydrosalpinx group had a significantly higher preclinical loss rate (22/59 = 37% vs 80/566 = 14%; P = 0.001), a significantly lower implantation rate (55/352 = 16% vs 795/3795 = 21%; P = 0.013), a trend toward a reduced delivery rate per transfer (28/106 = 26% vs 387/1150 = 34%; P = 0.066), a significantly higher ectopic pregnancy rate (5/59 = 8% vs 16/566 = 3%; P = 0.04), and a similar spontaneous abortion rate (9/37 = 24% vs 99/486 = 20%; P = 0.28) compared to the control tubal factor group. CONCLUSIONS: This study demonstrates a decrease in implantation rates and an increase in preclinical miscarriages and ectopic pregnancies in patients with hydrosalpinges compared to tubal-factor patients without sonographic evidence of dilated fallopian tubes.

Abortion, Spontaneous↗

PubMed1999

Expression of inhibin/activin subunits and their receptors and binding proteins in human preimplantation embryos.

PURPOSE: Our purpose was to study the role of inhibin/activin during embryogenesis. METHODS: Transcripts of inhibin/activin subunits (alpha, beta A, beta B), activin receptors (types I and II), and follistatin were detected by a reverse transcriptase-polymerase chain reaction in human reproductive cells and preembryos cultured alone or co-cultured with human endometrial cells. RESULTS: Transcripts of alpha, beta A, beta B subunits were all detected in granulosa luteal cells, but only beta A units were detected in endometrial stromal and decidualized cells. In human preimplantation embryos, none of these subunits were detected in embryos from the four-cell to the morula stage and only beta A subunits were detectable in blastocyst embryos. Activin receptors were detectable in all of the studied embryos and cells. Transcripts of beta A, activin receptors, and follistatin were differentially expressed in human preimplantation embryos cultured in vitro and their expressions were significantly enhanced with the presence of endometrial stromal cells. CONCLUSIONS: Our data suggest that there is a possible endometrium-embryo interaction via endometrial activins and preimplantation embryo receptors and that the embryonic expressions of these activins, their receptors, and binding proteins are dependent on embryonic stage.

Activin Receptors↗

PubMed1999

Autologous endometrial co-culture in patients with repeated failures of implantation after in vitro fertilization-embryo transfer.

PURPOSE: Our purpose was to evaluate the effect of coculture on preembryo development and clinical outcome. METHODS: Enrolled patients underwent a luteal-phase endometrial biopsy. The tissue was then enzymatically digested (collagenase) and the stromal and glandular cells were separated by differential sedimentation rates. These cells were cultured to confluence, released, and then cryopreserved until the patient's in vitro fertilization (IVF)-embryo transfer (ET) cycle. All normally fertilized oocytes were then placed on the co-cultured cells until transfer on day 3. Preembryo development on co-culture was compared to that in the patient's noncocultured previous cycle. Implantation and clinical pregnancy rates were compared to those in a control group of patients undergoing IVF during the study period who were matched for age, stimulation protocol, number of oocytes retrieved, and preembryos transferred. RESULTS: Twenty-nine women underwent 31 cycles of IVF-ET. On day 3 the overall mean number of blastomeres per preembryo on co-culture compared to that in the patient's previous cycle was 6.3 +/- 1.8 vs. 5.6 +/- 1.2 (P = 0.04). The average percentage of cytoplasmic fragments on co-culture compared to the previous cycle was 16 +/- 9% vs. 19 +/- 9% (P = 0.32). At transfer, after preembryo selection, the mean number of blastomeres per preembryo on co-culture compared to that in the patient's previous cycle was 6.8 +/- 1.6 vs. 6.6 +/- 1.3 (P = 0.5). The implantation and clinical pregnancy rates between co-culture and the matched control group were 15% (14/93) vs. 13% (16/124) (P = 0.79) and 29% (9/31) vs. 25% (10/40) (P = 0.45). CONCLUSIONS: There was a significant improvement in the average number of blastomeres per preembryo on co-culture compared to that in the patient's previous noncoculture cycle. The overall implantation and clinical pregnancy rates between co-culture and a matched control group were not significantly different.

Adult↗

PubMed1999

High seroprevalence of Borna virus infection in schizophrenic patients, family members and mental health workers in Taiwan.

Borna disease virus (BDV), a negative-strand RNA virus, has been reported to be associated with severe psychiatric disorders. The association is mainly based on the findings that patients with schizophrenia and depression have a higher seroprevalence rate of BDV-specific antibodies than controls. In addition, psychiatric patients were also found to have a higher detection rate of BDV transcripts in their blood than controls. By using an improved Western blot analysis, we first demonstrated that Chinese schizophrenic patients from Taiwan also have a higher seroprevalence of BDV-specific antibodies than controls (12.1% vs 2.9%, P< 0.001), providing support to the positive association between BDV and psychiatric disorders in our population. Because of the contagious nature of viral infection, we further examined patients' family members and mental health workers, who have close contact with patients. We found that both groups also have a higher seroprevalence of BDV-specific antibodies, 12.1% and 9.8%, respectively, than controls. This finding provides some evidence for a possible human-to-human transmission of Borna disease virus. Our finding needs further independent verification from other research groups and the clinical relevance of this preliminary observation deserves further study.

Adult↗

PubMed1999

The effect of sintered beta-dicalcium pyrophosphate particle size on newborn Wistar rat osteoblasts.

During recent years, sintered dicalcium phosphate (SDCP) has been shown to be an effective artificial bone filler for repairing bone defects. The goal of this study was to elucidate the effect of SDCP particle size on osteoblasts. Osteoblasts were mixed and cultured with various sized SDCP particles (0.5-3.0, 37-63, 177-250, and 420-841 microns) for 1 h, 3 h, 1 day, 3 days, and 7 days and then analyzed. The results show that the adding of smaller sized SDCP particles (0.5-3.0 and 37-63 microns) into osteoblast culture can significantly affect the cell counts of osteoblasts. The secretion of transforming growth factor-beta 1, alkaline phosphatase, and prostaglandin E2 in culture medium increased significantly. The changes were most significant and persisted longer in smaller particle groups. Small sintered dicalcium phosphate particles can inhibit the proliferation of the osteoblasts. The inhibitory effects of the smaller sized SDCP particles on the osteoblasts were mediated by the promotion of osteoblast differentiation and the increased synthesis of prostaglandin E2.

Alkaline Phosphatase↗

PubMed1999

Previously undetected Chlamydia trachomatis infection, immunity to heat shock proteins and tubal occlusion in women undergoing in-vitro fertilization.

The relationship between a previously undetected Chlamydia trachomatis infection, tubal infertility, immunity to heat shock proteins and subsequent in-vitro fertilization (IVF) outcome was evaluated. Women with tubal occlusion, with or without hydrosalpinges, and no history of C. trachomatis infection were tested for circulating antibodies to the human 60-kDa heat shock protein (Hhsp60), the C. trachomatis 10-kDa heat shock protein (Chsp10) and C. trachomatis surface antigens prior to their initial IVF cycle. Sera were obtained from 50 women whose male partners were infertile, 58 women with tubal occlusion but no hydrosalpinx and 39 women with tubal occlusions plus hydrosalpinx. Clinical pregnancies were documented in 68% of the women with male factor infertility. This was higher than the 43.1% rate in women with tubal occlusions (P = 0.04) and the 41% rate in women with hydrosalpinx (P = 0.02). C. trachomatis antibodies were present in one (2%) women with male factor infertility as opposed to 15 (25.9%) women with tubal occlusion (P = 0.003) and 13 (33%) with hydrosalpinx (P < 0.0001). Antibodies to Chsp10 were more prevalent in women with hydrosalpinx (46.8%) than in women with male factor infertility (P < 0.0001, 6%) or tubal occlusion (P = 0.0009, 15.5%). Hhsp60 antibodies were equally more prevalent in women with tubal occlusion plus (46.8%) or minus hydrosalpinx (41.4%) than in women with male factor infertility (P < 0.0002). Hhsp60 was more prevalent in those women positive for Chsp10 (P = 0.02) or C. trachomatis (P = 0.04) antibodies than in women lacking these antibodies. There was no relationship between any of the antibodies measured in sera and IVF outcome.

Adult↗

PubMed1999

Expression of the insulin-like growth factor-1 gene and its receptor in preimplantation mouse embryos; is it a marker of embryo viability?

Recent studies have demonstrated the importance of insulin-like growth factors (IGF) in mouse preimplantation development. We examined IGF-1 and IGF-1 receptor (IGF-1R) gene expression in a single blastomere of an early mouse embryo and compared it with subsequent embryo development in culture. Fertilized eggs and 2-cell embryos were obtained by tubal flushing in superovulated and mated female mice. Single cells were removed from embryos at cleavage stage between 3 and 8 cells using the standard embryo biopsy techniques. Individual blastomeres from each embryo were then assayed for the presence of IGF-1 and IGF-1R mRNA using reverse transcription-polymerase chain reaction. The biopsied embryos were washed in medium and placed in co-culture with murine endometrial cells. Embryonic development in culture was assessed and blastocyst grading was performed. IGF-1 gene expression was then examined for an association with in-vitro development. Eighty-seven embryos were biopsied. IGF-1R gene expression was detected in the majority of embryos tested and IGF-1 gene expression was detected in 34 of 81 (42%) embryos. A significant association between IGF-1 expression and blastocyst formation in vitro was found (P < 0.01). There was no association between IGF-1R expression and subsequent embryo development. We conclude that IGF-1 gene expression could potentially be used as a marker of embryo quality.

Actins↗

PubMed1999

Cytokine and prostaglandin E2 release from leukocytes in response to metal ions derived from different prosthetic materials: an in vitro study.

Cytokines produced by leukocytes in the periprosthetic membranes surrounding joint replacements have been implicated as causal agents in osteolysis and prosthetic loosening. In this study, we used an in vitro leukocyte culture system to monitor the response of leukocytes to various metal ions and their possible roles in the mechanism of aseptic loosening. Human peripheral leukocytes were isolated and incubated with various concentrations of Co2+, Cr3+, and Ti3+ ions. Leukocyte cell counts and the levels of the tumor necrosis factor-alpha (TNF-alpha), interleukin-1 (IL-1), interleukin-6 (IL-6) and prostaglandin E2 (PGE2) released into the media were analyzed at 1 h, 3 h, and 1, 3, and 7 day intervals. The results showed that adding different metal ions into leukocyte cultures did not affect the cell counts. Exposure of leukocytes to Co2+ ion increased the release of TNF-alpha, IL-6, and PGE2. Exposure of leukocytes to Cr3+ ion did not increase the release of TNF-alpha but increased the secretion of IL-6 and PGE2. In contrast, exposure of the leukocytes to Ti3+ ions was associated with a decrease in the release of TNF-alpha and PGE2 and a minimal change in IL-6 noted after 7 days' culture. The present study elucidated the possible mechanisms involved in periprosthetic osteolysis and the inflammatory response of human leukocytes to metal ions. We found that cobalt ion is the most potent stimulant for cytokines and prostaglandin secretion by leukocytes. This elucidation, in combination with other efforts to reduce the generation of wear debris and metal ions, may improve the longevity of orthopedic implants.

Cell Count↗

PubMed1999

Depressive disorders in Chinese patients with Alzheimer's disease.

OBJECTIVE: The present study was to investigate the prevalence and potential risk factors of depressive disorders in Chinese patients with Alzheimer's disease (AD). METHOD: A series of consecutive AD patients from the Memory Disorders Clinic of the Veterans General Hospital, Taipei were studied. Psychiatric diagnosis was made according to DSM-III-R criteria with the use of the Structured Clinical Interview for DSM-III-R (SCID). The Chinese version of the Cognitive Abilities Screening Instrument (CASI) and the Hamilton Depression Rating Scale (HDRS) were also applied. Primary caregivers were interviewed for the Clinical Dementia Rating (CDR) scale, the Barthel Index and the Alzheimer's Deficit Scale (ADS). RESULTS: Among 141 AD patients, seven (5.0%) were diagnosed with major depression, 11 (7.8%) with dysthymia and five (3.5%) with depressive disorder not otherwise specified. Women were at elevated risk for depressive disorders and had more severe symptoms of depression. CONCLUSIONS: The prevalence of depressive disorders among Chinese AD patients is in the middle of the range of western findings. The risk factor for depression is female gender.

Aged↗

PubMed1999

Heat shock protein expression during gametogenesis and embryogenesis.

When cells are subjected to various stress factors, they increase the production of a group of proteins called heat shock proteins (hsp). Heat shock proteins are highly conserved proteins present in organisms ranging from bacteria to man. Heat shock proteins enable cells to survive adverse environmental conditions by preventing protein denaturation. Thus the physiological and pathological potential of hsps is enormous and has been studied widely over the past two decades. The presence or absence of hsps influences almost every aspect of reproduction. They are among the first proteins produced during mammalian embryo development. In this report, the production of hsps in gametogenesis and early embryo development is described. It has been suggested that prolonged and asymptomatic infections trigger immunity to microbial hsp epitopes that are also expressed in man. This may be relevant for human reproduction, since many couples with fertility problems have had a previous genital tract infection. Antibodies to bacterial and human hsps are present at high titers in sera of many patients undergoing in vitro fertilization. In a mouse embryo culture model, these antibodies impaired the mouse embryo development at unique developmental stages. The gross morphology of these embryos resembled cells undergoing apoptosis. The TUNEL (terminal deoxynucleotidyl transferase-mediated X-dUTP nick end labeling) staining pattern, which is a common marker of apoptosis, revealed that embryos cultured in the presence of hsp antibodies stained TUNEL-positive more often than unexposed embryos. These data extend preexisting findings showing the detrimental effect of immune sensitization to hsps on embryo development.

Animals↗

PubMed1999

No association between alpha-1-antichymotrypsin polymorphism and Alzheimer's disease in Chinese.

A recent observation has shown that a common polymorphism in the alpha1-antichymotrypsin (ACT) confers a significant risk for Alzheimer's disease (AD). Furthermore, the apolipoprotein E epsilon4 allele (APOE*4) effect associated with AD risk is modified by the ACT polymorphisms. To evaluate the role of ACT polymorphism in AD, we conducted an association study of ACT polymorphisms in Chinese AD patients and normal controls. We found that the ACT polymorphism had no effect on the development of AD either alone or in combination with the APOE*4 allele.

Aged↗